It is known as shown in German OS 27 31 164 to provide an apparatus for regulating the position of an adjustable or movable member using a hydraulic apparatus with an operating fluid circuit having a two-way valve operating in two directions and with a control circuit connected to a pressure agent source for actuating the valve, the control circuit being connected to two control devices for the valve and having two adjustable valves or throttles, one of which is disposed between a supply tank and one of the control devices. The other adjustable throttle or valve is disposed between the connection of the control circuit to the second control device and supply tank. The control circuit additionally has two fixed throttles, each of which is connected between the pressure agent source and one of the control devices. In this apparatus, a control pressure in the control circuit is needed in order to cause movement of the slide of the two-way valve, which pressure, depending on the sensitivity of response of the slide, must be a multiple of the valve's minimum response pressure and wherein the product of the control accuracy of the mechanism, expressed in percent, and the multiple of that minimal response pressure equals 100. Considerable control pressures are therefore required.